Clutch Assembly

ABSTRACT

A sealed clutch and a clutch plate, the sealed clutch including a spline connector for connecting the sealed clutch by splined connection to a transmission shaft of an automotive transmission. The spline connector comprising a connector housing and a spline ring. The spline ring including an opening having a spline configuration for cooperating with a splined portion of a transmission shaft. The connector housing being secured within the sealed clutch and the spline ring being removably connectable to the connector housing to enable the spline ring to be removed and replaced with a different spline ring for cooperating with a splined portion of a different transmission shaft. The clutch plate has a pair of drive plates having a coaxially aligned openings and a spline connector mounted between them. The outer diameter of the spline ring being slightly less than the inner diameter of the opening of one of the drive plates and a removable retainer being interposed between the spline connector and the drive plate to retain the spline ring, whereby removal of the removable retainer enables removal of the spline ring from the spline connector through the opening of the drive plate.

PRIORITY CROSS-REFERENCE

The present application claims priority from Australian ProvisionalPatent Application No. 2020902617 filed 27 Jul. 2020 the contents ofwhich is to be considered to be incorporated into this specification bythis reference.

TECHNICAL FIELD

The present invention relates to a clutch assembly for an automotivevehicle and more particularly to a clutch assembly that can be mountedwithin different drivetrains of different vehicles. The clutch assemblycan thus be termed as a “universal” clutch assembly in that the clutchassembly of the present invention facilitates attachment of one form ofclutch universally within vehicles that employ different drivetrainforms including different forms of transmission gear spline shafts.

The invention also relates to a sealed clutch for use in a clutchassembly of the above kind and to a clutch plate for use in a sealedclutch.

BACKGROUND OF INVENTION

The discussion of the background to the invention that follows isintended to facilitate an understanding of the invention. However, itshould be appreciated that the discussion is not an acknowledgement oradmission that any aspect of the discussion was part of the commongeneral knowledge as at the priority date of the application.

Vehicle manufacturers are continuously innovating and optimising vehiclecomponents in order develop new and improved vehicles. Amongst thecomponents that are targeted for optimisation or re-design is the clutchassembly that connects between the vehicle engine and transmission. Inparticular, when manufacturers release a new vehicle, the clutch systemis typically different to the outgoing model. Over the past 70 years,vehicle manufacturers have developed over 5000 different clutchconfigurations for different vehicles. The applicant itself stocks over4000 different clutch kits that are used for replacement of worn ordamaged clutches.

As vehicle manufacturers seek increases in engine torque output, fueleconomy and improvements in noise, vibration, and harshness (NVH), theclutch assembly is often modified or re-designed. Clutch assemblies aregradually becoming more complex to be able meet vehicle performancestandards. It is expected that the increased complexity in clutchassemblies will see the cost of the average clutch system increaseapproximately 45% from USD$171 as at 2018 to approximately USD$250 by2025.

Existing clutch kits (kits of parts that form a clutch assembly,including a friction disc, pressure plate, diaphragm etc) are notconsidered to be particularly versatile and can only be applied to avery limited number of vehicles. Of the currently available clutch kits,approximately only 260 kits can fit onto more than 10 differentvehicles. The lack of cross-vehicle compatibility of clutch kitsprovides a burden on inventory management for manufacturers andsuppliers. Typical installers do not have the capacity (either in termsof space or money) to carry the enormous inventory required to be ableto replaces clutches across a wide range of vehicles. Manufacturers,suppliers and installers are therefore heavily reliant on expeditedfreight systems to be able to promptly provide customers (theinstallers) with replacement kits for specific vehicles when the clutchof that vehicle requires replacement.

Repair rather than full replacement of a clutch is rarely an optiongiven that, due to the large cost and inconvenience associated withattending an automotive workshop to deal with clutch issues, vehicleowners usually run the clutch assembly to failure before having amechanic replace it. But this results in a significant repair activity,involving raising the vehicle on a hoist, removing various parts of thevehicle drivetrain including the clutch, ordering and thereafterinstalling a new clutch and replacing the remaining drivetrain parts.Moreover, it is usually necessary for the vehicle to be assessed first,to establish that the existing clutch does need to be replaced and sobefore a clutch kit is ordered, the vehicle usually needs to be raisedon a hoist and if the decision is to replace the clutch often thevehicle will be left on the hoist while the new clutch is ordered anddelivered. The vehicle thus tends to occupy valuable space and equipmentin the automotive workshop (automotive workshops tend to have limitednumbers of hoists) over at least two days (but often more where deliveryof the new clutch is delayed or where delivery is to rural or remotelocations), while the vehicle owner is inconvenienced by having thevehicle off the road for an extended period of time, often having torent a replacement vehicle until their own vehicle is repaired. Becauseof this, manufacturers and suppliers have established elaborate andexpensive inventory and logistic networks to expedite the delivery ofclutch kit orders. The establishment of these inventory and logisticnetworks require significant capital expenditure in addition to ongoingrunning costs.

As there exists a large number of clutch kits, it is common for aninstaller to mistakenly order a clutch kit that is incompatible with theparticular vehicle being repaired, or with the particular vehicle model.This contributes to additional supply chain expenses to the supplier,the mechanic and the customer given that the wrongly ordered clutch kitmust be returned and the correct clutch kit delivered. Moreover, giventhe vast number of clutches currently in use, it is often the case thatmechanics and suppliers encounter delays and difficulty in sourcing thecorrect clutch kit.

Further, as each clutch kit is to be fitted to a certain alignment andconfiguration, installers are required to diligently review installationspecifications, and manufacturers are required to provide installers andsuppliers with support through training sessions and instructionmanuals. Where an installer is unable to align a clutch to the specifiedconfiguration, the life of the new clutch can be significantlycompromised, and may potentially cause damage to surrounding vehiclecomponents, i.e. the engine on one side of the clutch and thetransmission on the other side.

As part of the replacement of a clutch, the flywheel attached to thecrankshaft of the engine will also be assessed for wear or damage. Thisoccurs because traditional clutches frictionally engage a surface of theflywheel for torque transmission. That flywheel surface almost alwaysneeds to be refurbished by re-grinding and so this adds to further timeand expense in removing the flywheel and in sending it for grinding.

The useful life of a standard clutch is approximately 100,000kilometres. As the average life of a vehicle is 250,000 kilometres, atleast two clutch replacements are inevitable. As explained above, theprocess to change a clutch is labour intensive and time-consuming andcan take approximately two to four days to complete. Throughout thistime the vehicle owner will be without their vehicle and the automotiveworkshop will have the vehicle occupying garage space and resourceswhile dormant.

For at least the forgoing reasons, the applicant has proceeded todevelop new clutch assemblies with the intention to mitigate oreliminate some or all of the onerous aspects of a conventional vehicleclutch replacement. In particular, the applicant considers there to be aneed for a new form of clutch assembly which can be fitted to more thanone type of vehicle so that a specific form or type of clutch assemblyis not required for each different vehicle or each small group ofvehicles.

SUMMARY OF INVENTION

According to the present invention there is provided a sealed clutch,the sealed clutch including a spline connector for connecting the sealedclutch by splined connection to a transmission shaft of an automotivetransmission,

-   -   a. the spline connector comprising a connector housing and a        spline ring,    -   b. the spline ring including an opening having a spline        configuration for cooperating with a splined portion of a        transmission shaft,    -   c. the connector housing being secured within the sealed clutch        and the spline ring being removably connectable to the connector        housing, to enable the spline ring to be removed and replaced        with a different spline ring for cooperating with a splined        portion of a different transmission shaft.

A sealed clutch as referred to above and throughout this specificationis a clutch which does not frictionally engage the face of a flywheel.In some forms, the clutch has base plate and a pressure plate and anintermediate plate between them and the friction linings of a clutchplate are positioned on either side of the intermediate plate. In otherforms, the clutch could have just a single friction lining between abase plate and a pressure plate and no intermediate plate, or it couldhave more than two plates, such as three of four plates (known as tripleor quad clutches). The clutch plates drive a transmission shaft and thepressure plate is axially movable within the clutch to frictionallyengage and disengage the clutch plates. Sealed clutches can also bemodular clutches and in certain regions are also known as‘pre-assembled’clutches. In addition, clutch plates are also known asclutch discs and so the use of “plate” and “disc” in this specificationis interchangeable and should be considered to be referring to the sameitem of a clutch.

Many of the benefits provided by the present invention occur because theclutch or friction plate of an existing clutch is required to fit aparticular splined portion of a transmission shaft. However, because thesealed clutch of the present invention employs a spline connector havinga removable and replaceable spline ring, if the spline ring currentlyfitted to the sealed clutch does not suit a particular transmissionshaft, the spline ring can be removed and replaced with a differentspline ring that does suit the transmission shaft. Advantageously, thisallows one general form of sealed clutch to be applied to a range ofvehicles that have different transmission shafts.

This has another advantage which is that the consumer is not limited tothe clutch that was originally installed in the vehicle, but rather, thenew clutch that is installed can be of an improved type, or at least adifferent type, that has not heretofore been otherwise installable inthat vehicle. For example, a single disc clutch that is supplied asoriginal equipment with a vehicle, might be replaced by a twin disc ortriple disc sealed clutch for improved performance or longevity. Thebenefit here is that the vehicle owner has more choice than previously,because previously, the vehicle owner was limited to the particularclutch that fitted the vehicle. By use of the present invention, thevehicle owner can not only choose to replace the previous clutch with aclutch having generally the same performance and longevity, but thevehicle owner can alternatively select a different clutch for thereplacement, which might be cheaper, of higher performance, or ofgreater longevity. The vehicle owner now has a choice that might nothave been available in the past.

The present invention thus enables a reduced number of clutch kits tomeet the needs of a large number of vehicles, so that a reduced numberof clutch kits need to be manufactured, stored and delivered. This willhave an advantageous effect in reducing costs for manufacturing (lessdifferent component parts will be needed), storage space, delivery andwill reduce the amount of errors made during selection and ordering ofclutch kits. Moreover, it is more likely that automotive workshops willbe able to carry stock that will allow them to have suitable clutchparts on hand whereby an order and subsequent delivery of parts is notrequired. This would facilitate better scheduling of clutch repairs sothat replacement of a clutch could take place on the day the vehicle isprovided to the automotive workshop, with all the associated benefits toboth the customer and the workshop. The applicant envisages supplyingclutch kits with a set of 10 different spline rings to suit the 10 mostpopular transmission shaft configurations, so that the one sealed clutchcan be used across those 10 most popular transmission shaftconfigurations simply by selecting the appropriate spline ring.

While the connector housing can take any suitable form, applicant hasdeveloped a connector housing that includes an opening and the splinering is secured within the opening against rotation relative to theconnector housing. The outer surface of the spline ring can beconfigured to cooperate with the inner surface of the opening and forexample, the opening of the connector housing can be a non-round openingand the outer surface of the spline ring can have a complementary shapeand be closely received within the opening, so that the spline ring iscaptured within the opening of the connector housing against relativerotation.

In some forms of the invention, the opening of the connector housing andthe outer surface, circumference or periphery (hereinafter “outerperiphery”) of the spline ring are generally circular and a suitableconnection arrangement is employed to connect and secure the spline ringwithin the opening of the connector housing. In one form of theinvention, while the opening of the connector housing and the outerperiphery of the spline ring are each generally circular, one of theopening and the outer periphery includes one or more radially extendingprojections and the other of the opening and the outer peripheryincludes one or more radially extending recesses, whereby the one ormore projections are received within the one or more recesses when thespline ring is received within the opening of the connector housing, tolocate the spline ring against rotation relative to the connectorhousing. A sealed clutch according to the invention thus could employone radially extending projection and one radially extending recess, ora greater number, such as two or three sets of projections and recesses.

While the one or more radially extending projections can take anysuitable form, this arrangement would be satisfied by the use of a keyor keys, that each insert into aligned recesses or grooves formed ineach of the opening of the connector housing and the outer periphery ofthe spline ring and that connects between the connector housing and thespline ring. In other forms of the invention, the one or more radiallyextending projections can comprise a plurality of radially extendingteeth. These teeth can be spaced apart equidistantly. In this form ofthe invention, the teeth of the connector housing or the spline ring arereceived with the recesses of the spline ring or the connector housingto secure the spline ring against rotation relative to the connectorhousing. The teeth can be formed as or similar to gear teeth.

In the above arrangement in which the opening of the connector housingand the outer periphery of the spline ring are each generally circular,the connector housing and the spline ring will be coaxial when connectedtogether.

In the above arrangement in which the connector housing and the splinering are connected together by radially extending projections thatextend into one or more radially extending recesses, removal of thespline ring from the connector housing can be by axial movement of thespline ring relative to the connector housing. That is, when connected,the spline ring will be secured against rotation relative to theconnector housing but will not be secured against relative axialmovement. Accordingly, it is necessary for the spline ring to beprevented from axial release from the connector housing when the splinering is installed in the connector housing within a sealed clutch. Forthis, a removable retainer can be employed that can be removed byinstallation personnel when removal and replacement of the spline ringis required. A removable retainer can take any suitable form, but insome forms of the invention, the removable retainer is a circlip thatseats within an annular groove formed in the opening of the connectorhousing and that overlies the spline ring to act as a barrier to axialegress of the spline ring from the connector housing.

The use of a circlip can prevent egress of the spline ring from theconnector housing in one axial direction, or a pair of circlips can beemployed on either side of the spline ring to prevent egress of thespline ring from the connector housing in each axial direction. However,if a single circlip is used the sealed clutch can be arranged to securethe spline ring against removal from the connector housing in the otheraxial direction by engagement with other components of the sealed clutchso that removal of the spline ring from the connector housing is in oneaxial direction only and once the single circlip has been removed.

A sealed clutch according to the invention can include a pair of spacedapart drive springs that provide for vibration damping. The drivesprings can be straight or curved and can each comprise a single spring,or multiple springs. The drive springs can comprise coil springs oralternative springs, such as polymer springs. The drive springs can beof the kinds disclosed in applicant's previous International PCTapplications published as WO2013/170288 and WO2014/194358.

Each drive spring will have opposite ends and the connector housing canbe in engagement with the opposite ends so that rotation of theconnector housing is operable to apply a compressive load to the drivesprings, while the drive springs resist connector housing rotation andby that resistance provide vibration damping of the connector housing.The connector housing is expected to be rotatable through up to about30-50 degrees, although the exact amount is dependent on the design ofthe drive springs and the degree and form of vibration damping required.

The connector housing can have any suitable configuration to engage theopposite ends of the drive springs and in one form, the connectorhousing comprises a connector body in which the opening for receipt ofthe spline ring is provided and the connector housing has abutments orprojections extending from the connector body into engagement with theopposite ends of the drive springs.

A sealed clutch according to the invention will have a central axisabout which the clutch rotates in use, and in some forms of theinvention, the drive springs are located symmetrically on opposite sidesof the central axis and are spaced apart equidistantly about the centralaxis. There will often be two drive springs (comprising single ormultiple springs as discussed above), but the invention contemplates agreater number of drive springs such as three of four drive springs.Where two drive springs are provided, the connector housing can have apair of abutments extending from opposite sides of the connector bodyand into engagement with the opposite ends of the drive springs. Asingle abutment can extend into engagement with the opposite ends of twodrive springs. The engagement may not be permanent but may occur whenthe connector housing rotates sufficiently to engage the end of a drivespring, but permanent connection between the connector housing and thedrive springs assists to prevent rattling within the sealed clutch. Theabutment thus needs to extend between or bridge between the two oppositeends of two drive springs. Alternatively, the connector housing can havea separate abutment for engaging each end of the drive springs. Wherethree drive springs are provided, the connector housing can have threespaced apart abutments extending from the connector body, with eachabutment extending into engagement with the opposite ends of two drivesprings, or the connector housing can have six abutments with eachabutment extending into engagement with one drive spring end.

The abutments can have tapered side walls for engaging the ends of thedrive springs substantially normal or square to the axis of the drivesprings at the ends of the drive springs.

In some forms of the invention, a sealed clutch will include a clutchplate that has a pair of drive plates that define an internal cavitybetween them. The drive plates can each have a coaxially aligned openingthrough which the splined portion of a transmission shaft can extend.The spline connector of the sealed clutch is housed within the cavityand the opening of the spline ring is coaxial with the openings of thedrive plates. The spline connector is rotatable relative to the driveplates against the bias of the drive springs for applying a compressiveload to drive springs that are mounted to the drive plates. The drivesprings can be mounted fully or partially within the internal cavitybetween the drive plates.

The spline ring can be removable through one of the drive plates orthrough both of the drive plates. In some forms of the invention,removal of the spline ring is through one drive plate only and in theseforms of the invention, the outer diameter of the spline ring can beslightly less than the inner diameter of the opening of the drive platethrough which the spline ring is removable. To prevent the spline ringfrom release from the connector housing through the drive plate, theremovable retainer discussed above (a circlip for example) can beincluded in the opening of the connector housing to retain the splinering connected to the connector housing against axial release. Otherforms of removable retainer can alternatively be employed, such asremovable grub screws, or a ring similar to a circlip but which screwsinto the opening of the connector housing. In this form of theinvention, removal of the removable retainer enables removal of thespline ring from the spline connector through the opening of the driveplate.

In a more specific form of the invention, the pair of drive platescomprises first and second drive plates and a first axial end of theconnector housing is rotationally seated against a facing surface of thefirst drive plate that extends about the opening of the first driveplate and a second and opposite axial end of the connector housing isrotationally seated against a surface of the second drive plate thatextends about the opening of the second drive plate.

The sealed clutch can include one or more biasing springs to apply aload to the movable components within the internal cavity between thedrive plates in order to resist rattling between the components. In someforms of the invention, the sealed clutch can include at least two waveor spring washers between the axial ends of the connector housing andthe drive plates to apply opposing loads to the movable componentswithin the internal cavity between the drive plates for resistance torattling. Where wave or spring washers are employed between the axialends of the connector housing and the drive plates along with thecirclip retainer discussed above, the circlip can be positioned betweenthe spline ring and a wave or spring washer and the circlip can beremovable through the wave or spring washer and through the drive platefor subsequent removal of the spline ring.

The wave or spring washers can interact with a washer holder or locator(hereinafter “washer holder”) that assists to secure the wave or springwashers in place. For example, a wave or spring washer can have an inneropening defined by an inner edge and the inner edge can have one or morerecesses and likewise, the opening of the second and adjacent driveplate is defined by an inner edge and that inner edge can have one ormore recesses in alignment with the one or more recesses of the inneropening of the wave or spring washer. A washer holder can be interposedbetween the wave or spring washer and the second axial end of theconnector housing and the washer holder can include one or moreprojections which extend into the one or more recesses of the wave orspring washer and the opening of the second drive plate to locate boththe washer holder and the wave or spring washer against rotationrelative to the second drive plate. The recesses can be grooves or slotsor the like. The washer holder can be free to rotate relative to thesecond axial end of the connector housing.

A wave or spring washer can also be interposed between the first axialend of the connector housing and the facing surface of the first driveplate, and a washer holder or locator (hereinafter “washer holder”) canbe interposed between the wave or spring washer and the first axial endof the connector housing. The washer holder can assist to locate theconnector housing in coaxial relationship with the opening of the firstdrive plate and can transfer biasing load from the wave or spring washerto the spline ring to maintain the spline ring within the connectorhousing and, where a circlip retainer is employed as discussed above,the washer holder can transfer biasing load from the wave or springwasher to the spline ring to maintain the spline ring in connectionwith, such as pressing against, the circlip.

The washer holder interposed between the first axial end of theconnector housing and the facing surface of the first drive plate caninclude projections that extend into engagement with the connectorhousing and which fix the washer holder against rotation relative to theconnector housing. Thus, the connector housing, the spline ring and thewasher holder are located against rotation relative to one another. Thewasher holder can be free to rotate relative to the wave or springwasher.

The washer holder can be formed as a ring and the projections can extendaxially toward the second drive plate and a circular lip can extendaxially toward the first drive plate. The outer diameter of the lip canbe a close fit within the inside diameter of the opening of the firstdrive plate to locate the washer holder relative to the first driveplate.

The washer holder in the above embodiment can also constitute a spacerto space the spline connector from an adjacent drive plate. The spacercan vary in axial depth to accommodate clutch plates that have differentnumbers of friction linings. Thus, a clutch plate that has a pair offriction linings (a twin clutch plate) has a different axial depth orthickness compared to clutch plates that have triple or quad frictionlinings. With triple or quad clutch plates, the spline connector will bepositioned further from the adjacent drive plate and so a spacer ofgreater axial depth than that used in a twin clutch plate is required.Three separate spacers can be provided for separate use with twin,triple and quad clutch plates. The spacers can be plastic parts. Thisenables them to have a heat insulating capacity as well.

Each of the washer holders can be plastic to insulate against thebuild-up of heat when the spline ring and the connector housing rotaterelative drive plates, while the different material of the washerholders positioned between the metal wave or spring washers and themetal spline connector can reduce wear within the sealed clutch.

BRIEF DESCRIPTION OF DRAWINGS

In order that the invention may be more fully understood, someembodiments will now be described with reference to the figures inwhich:

FIG. 1 is a perspective view of a sealed clutch and flywheel assemblyaccording to the present invention.

FIG. 2 is an exploded view of the sealed clutch and flywheel assembly ofFIG. 1 .

FIG. 3 is a cross-sectional view of the sealed clutch of FIG. 1 .

FIG. 4 is perspective view of the clutch plate of the sealed clutch ofFIG. 1 .

FIG. 5 is an exploded perspective view of the clutch plate of the sealedclutch of FIG. 4 .

FIGS. 6A, 6B and 6C are views of a connector housing, a spline ring anda combination connector housing and spline ring respectively.

FIG. 7 is an exploded perspective view of the clutch plate of the sealedclutch of FIG. 4 taken from the opposite perspective to FIG. 5 .

FIG. 8 is perspective view of the clutch plate of the sealed clutch ofFIG. 1 taken from the opposite perspective to FIG. 4 .

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a flywheel 10 to which a clutch assembly20 is connected. The flywheel 10 includes an outer ring 11 within whichthe majority of the weight of the flywheel 10 is concentrated. Theflywheel 10 connects to the crank shaft of an engine, while the clutchassembly 20 connects to the transmission shaft of an automotivetransmission. The clutch assembly 20 is of the kind that is described intwo co-pending patent applications that the present applicant has filedsimultaneously with the present application. The content of thespecifications of Australian Provisional patent applications 2020902618and 2020902619 is to be considered to be incorporated into thisspecification by this reference.

FIG. 1 shows that the clutch assembly 20 includes a connection ring 22in connection with the flywheel 10, a spacer 24 and a sealed clutch 26.The clutch assembly 20 does not connect to the flywheel 10 and it thusvaries from traditional clutch installations, in which the clutch wouldconnect directly to and frictionally engage with the flywheel. In thepresent invention, the sealed clutch 26 connects to the flywheel eitherdirectly via the spacer 24, or via a combination of the spacer 24 andthe connection ring 22 as shown in FIG. 1 .

FIG. 2 is an exploded view of the flywheel 10 and the clutch assembly 20of FIG. 1 and shows that the connection ring 22 includes openings 23through which fasteners can extend for connection with openings 25 inthe flywheel 10. The spacer 24 connects to the connection ring 22 bylugs 27 that are received and fixed within recesses in the spacer 24.The sealed clutch 26 of FIG. 3 attaches to the spacer 24 via lugs 29that are received and fixed within recesses 31 in the spacer 24. In atraditional clutch installation, the clutch would connect directly tothe flywheel and would frictionally engage the flywheel surface 33 whenthe clutch was engaged. In the illustrated arrangement, the sealedclutch 26 is spaced from the surface 33 and so there is no engagementwith that surface when the clutch is engaged.

The sealed clutch 26 is shown in cross-sectional view in FIG. 3 . FIG. 3also shows the connection ring 22 and the spacer 24 in cross-section. Inrelation to the sealed clutch 26, this comprises a top plate 28, a baseplate 30, an intermediate or friction plate 32 and a pressure plate 34.Friction linings 36 are attached to the periphery of a clutch platewhich is generally marked 38 and are located between the base plate 30and the intermediate plate 32, and between the intermediate plate 32 andthe pressure plate 34. The clutch plate 38 extends to a centre hub 40.The centre hub 40 is, in use, in splined connection with the splined endof a transmission shaft (not shown) that extends to the transmission ofthe vehicle. As previously explained herein, different transmissionshave differently configured transmission shafts including differentlyconfigured spline connections with which the centre hub 40 is requiredto engage. The present invention provides a removable spline connectorso that the sealed clutch 26 can engage and thus be suitable for usewith a variety of differently configured transmission shafts.

The general operation of the sealed clutch 26 would be evident to aperson skilled in the art, but briefly, the clutch assembly 20 connectsto the flywheel 10 on one side (via the connection ring 22 and thespacer 24), and to the transmission shaft on the other side (via thecentre hub 40). In the state shown in FIG. 3 , the friction linings 36are in firm frictional engagement with (or are sandwiched between) thepressure plate 34, the intermediate plate 32 and the base plate 30, sothat torque delivered from the flywheel 10 to the clutch 26, rotates theclutch plate 38 which drives rotation of the centre hub 40 and theconnected transmission shaft to drive the transmission of the vehicle.To disengage the clutch 26, pressure is applied to the diaphragm springs42 at a radial inward portion of the springs 42, which allows thepressure plate 34 to lift slightly and thus to frictionally disengagethe friction linings 36 of the clutch plate 38 so that the clutch plate38 no longer drives the centre hub 40 and the transmission shaftconnected to the hub 40, so that the transmission of the vehicle is nolonger driven.

Thus, rotation of the clutch plate 38 is as a result of frictionalengagement within the clutch 26 and, in contrast with traditionalclutches, no frictional contact with the flywheel 10 is required.Because of this, the arrangement of the invention has major benefits, inthat the requirement to refurbish the friction surface of the flywheelor to replace the entire flywheel is no longer necessary, or is nolonger as frequent as with traditional clutches.

The present invention is directed to a form of sealed clutch whichincludes a spline connector that can be configured for cooperating withdifferently configured spline connections of different automotivetransmission shafts so that the one sealed clutch can connect to morethan one form of transmission shaft. The centre hub 40 shown in FIGS. 2and 3 includes a spline connector according to the present invention andwhich is shown in more detail in the figures that follow.

FIG. 4 illustrates a clutch plate 50 according to the invention, thatcan be employed in a sealed clutch such as the sealed clutch 26 of FIGS.2 and 3 . The clutch plate 50 can thus be installed in a sealed clutch26 to assume the position of the clutch plate 38 of FIG. 3 . The clutchplate 50 includes friction linings 52, drive springs 54 and upper andlower drive plates 56 within which the drive springs 54 are mounted(only the upper drive plate is visible in FIG. 4 , but a similar driveplate is positioned below the drive plate that is visible in FIG. 4 )and a spline connector 58. FIG. 4 only shows the spline connector 58from above and in an assembled form but shows that the spline connector58 has a central circular opening 60 that has an internal splined wall62 for engaging with the splined portion of a transmission shaft.

The drive plates 56 connect together and define an internal cavitybetween them. The friction linings 52 connect or attach to the peripheryof the drive plates 56, while the spline connector 58 is housed withinthe cavity.

FIG. 5 illustrates the clutch plate 50 of FIG. 4 in exploded view. FIG.5 shows the spline connector 58 in more detail (but reference numeral 58does not appear in FIG. 4 ) and from FIG. 5 it can be seen that thespline connector 58 comprises a connector housing 64 and a spline ring66. The connector housing 64 and spline ring 66 are shown respectivelyseparately and connected in FIGS. 6A, 6B and 6C.

The connector housing 64 has a generally circular opening 68 (FIG. 6A)which includes a plurality of equidistantly spaced projections 70 thatproject radially inwardly of the opening 68 and that have slightlyinclined side walls. The spline ring 66 has a generally circularperiphery which includes a plurality of equidistantly spaced projections74 extending radially outwardly therefrom. Between the projections 70 ofthe connector housing 64 are recesses 72 and the projections 70 andrecesses 72 are configured for receipt of the projections 74 of thespline ring 66, with the projections 74 of the spline ring 66 beingreceived within the recesses 72 of the connector housing 64.

FIG. 6C shows the connector housing 64 and the spline ring 66 inconnection and by the interconnection between the projections 74 andrecesses 72, the connector housing 64 and the spline ring 66 areconnected together against relative rotation about the coaxial axes ofthe respective openings 60 and 68. However, in the arrangementillustrated, the spline ring 66 is not located axially (along the axisof the openings 60 and 68) with respect to the connector housing 64.That is, in absence of axial location, the spline ring 66 can passthrough the connector housing 64. However, in the assembled clutch plate50, the spline ring 66 is captured in the connector housing 64 againstaxial movement as hereinafter described.

FIG. 7 is a further exploded view of the clutch plate 50, taken from theopposite perspective of FIG. 5 .

The connector housing 64 of the spline connector 58 has opposite axialends which face respective drive plates 56. Interposed between therespective opposite axial ends are rings 76, 78, 80 and 82. Also shownis a circlip 79. FIG. 7 is taken from an angle which shows that therings 78 and 80 include projections for a purpose that is describedhereinafter.

The rings 76 and 82 are wave or spring washers that apply load betweenthe spline connector 58 and the drive plates 56 in order to resistrattling between the components but to still allow smooth rotation ofthe spline connector 58 relative to the drive plates 56. The ring 78 isa spacer and the ring 80 is a washer holder.

The spacer 78 includes a plurality of axially extending projections 84,while the washer holder 80 also includes axially extending projections86. The projections 84 of the spacer 78 extend into the recesses 72 ofthe connector housing 64. These are the same recesses 72 that theprojections 74 of the spline ring 66 extend into, but as shown in FIG. 7, the projections 74 have an axial length which is less than the fullaxial length of the spline ring 66, so that the recesses 72 can axiallyaccommodate both the projections 84 and the projections 74. Receipt ofthe projections 84 within the bottom ends of the recesses 72 fixes thespacer 78 against rotation relative to the connector housing 64.

As shown in FIG. 5 , the spacer 78 further includes an axially extendingcircular lip 88 that is received through the opening 90 of the wave orspring washer 76 with the outer diameter of the lip 88 being a close fitwithin the inner diameter of the opening 90 to coaxially align the rings76 and 78. The wave or spring washer 76 seats against the surface 92 ofthe drive plate 56 and against the facing surface 94 (see FIG. 5 ) ofthe spacer 78.

On the opposite side of the connector housing 64, the washer holder 80seats against the facing surface 96 of the connector housing 64 and theprojections 86 extend axially through the indents or recesses 98 formedin the inside wall 100 of the wave or spring washer 82 so that therespective rings 80 and 82 are fixed against relative movement. Theprojections 86 further extend into the recesses 102 (see FIGS. 5 and 7 )of the drive plate 56 thus further locating the rings 80 and 82 againstrotation relative to the drive plate 56. The wave or spring washer 82seats against the surface 104 (see FIG. 5 ) of the drive plate 56.

The rings 78 and 80 are plastic in the embodiment illustrated. Thespacer or ring 78 rotates with the spline ring 66 and the connectorhousing 64 and relative to the wave or spring washer 76. The plasticspacer 78 insulates against the build up of heat when the spline ring 66and the connector housing 64 rotate relative to the wave or springwasher 76 and the different material of the spacer 78 relative to themetal wave or spring washer 76 and the metal spline ring 66 and theconnector housing 64 reduces wear.

The spacer 78 can vary in axial depth or thickness to accommodate clutchplates that have different numbers of friction linings. A pair offriction linings 52 is shown in FIGS. 5 and 7 , but triple and quadfriction lining clutch plates can alternatively be employed and thesehave a greater axial depth than the pair of friction linings 52 shown inFIGS. 5 and 7 . In order to use the same form of spline ring 66 andconnector housing 64 as shown in the figures, spacers of different axialdepth can be employed so that the selected spacer can extend through thegreater axial depth of the triple and quad friction lining clutch platesto engage with the connector housing 64. In this respect, the connectorhousing 64 and the spline ring 66 can remain the same size regardless ofwhether they are paired with the double friction lining clutch plate 50,or with triple and quad friction lining clutch plates. Three separatespacers 78 can be provided for separate use with twin, triple and quadfriction lining clutch plates. The spacers can vary by the axialthickness of the ring from which the projections 84 extend varying inthickness. Because the spacer 78 is a plastic part, it is relativelycheap and easy to provide in the three different forms.

The circlip 79 forms a removable retainer that provides an axial barrieragainst egress of the spline ring 66 from the connector housing 64. Thecirclip 79 is received within a groove G (see FIGS. 5, 6A and 7 ) formedthrough the projections 70 and the recesses 72 of the connector housing64. The circlip 79 thus overlies one axial side of the spline ring 66,in particular overlying the projections 74 of the spline ring 66. Thecirclip 79 can be contracted radially to release from the groove G andcan then be removed through the rings 80 and 82 and then through theopening 57 of the adjacent drive plate 56. Once removed, the barrieragainst removal of the spline ring 66 from the connector housing 64 isno longer in place and so the spline ring 66 can also be removed throughthe rings 80 and 82 and then through the opening 57 of the adjacentdrive plate 56 and replaced with a different spline ring as suitable forthe particular transmission shaft to which the spline connector 58 is tobe connected. Once the new spline ring has been inserted, the circlip 79can be reinstalled into the groove G and the new spline is then securedwithin the connector housing 64.

The spline ring 66 cannot be removed through the rings 76 and 78. Therings 76 and 78 overlie the projections 74 of the spline ring 66, sothat the openings of the rings 76 and 78 are not large enough for thespline ring 66 to fit through. This can be seen in FIG. 4 in which theprojections 74 of the spline ring 66 are not visible. In contrast, inFIG. 8 , the projections 74 of the spline ring 66 are visible and so inabsence of the circlip 79 (not visible in FIG. 8 ), the spline ring 66is free to be removed from within the clutch plate 50 without either ofthe rings 80 and 82 being removed.

In the assembled state of the clutch plate 50, the openings 57 of thedrive plates 56 and the openings 60 and 68 of the connector housing 64and the spline ring 66 are coaxially aligned to allow the splinedportion of a transmission shaft to extend therethrough. Moreover, asexplained above, the spline connector 58 is mounted to be rotatablerelative to the drive plates 56, so that the spline connector 58 canapply a compressive load to the drive springs 54 for the purpose ofvibration damping. For this, the connector housing 64 includes radialextensions 106. The extensions 106 are positioned between similar shapedformations 108 of the drive plates 56 when the drive plates 56 areassembled together to form the cavity that houses the spline connector58.

In a resting state of the clutch plate 50 side surfaces 110, 112 of theextensions 106 and the formations 108 are engaged by abutting surfaces114 of the drive springs 54 (see FIGS. 5 and 7 ). By that engagement,the connector housing 64 and thus the spline connector 58 is locatedagainst rotation relative to the drive plates 56. However, to dampenvibrational loads, the connector housing 64 of the spline connector 58will rotate, rotating the radial extensions 106 against the bias of thedrive springs 54. The drive springs 54 will compress with one of theabutting surfaces 114 of each of the drive springs 54 disengaging from afacing side surface 112 of the formations 108 as it is driven away fromside surface 112 to compress by a respective extension 106. The radialextensions 106 are mounted in slightly axially spaced relationship withfacing surfaces of the formations 108 and rotate relative to theformations 108 with the relative rotation being in the order of up toabout 30-50 degrees.

FIG. 8 is a view of the clutch plate 50 from the side of the ring 82(the opposite side of FIG. 4 ) and from this figure, it can be seen thatthe ring 82 is captured at its outer diameter beneath the inner diameterof the drive plate 56 about the opening 57—see the circled region markedC in FIG. 8 . In other words, the inner diameter of the opening 57 ofthe drive plate 56 overlies a portion of the ring 82 so that the ring 82cannot be removed when it assumes its normal or operational condition asshown in FIG. 8 . Thus, the ring 82 and the ring 80 are held in place bythe drive plate 56. The circlip 79 is shown in FIG. 8 within the grooveG and overlying the projections 74 of the spline ring 66 (theprojections 74 are obscured by the circlip 79). The circlip 79 can beaccessed with the rings 80 and 82 in place and through the opening 57 ofthe drive plate 56 and once the circlip 79 is removed, the spline ring66 can also be removed and replaced. This is because the outer diameterof the spline ring 66 is less than the inner diameter of the openings ineach of the rings 80 and 82 and the inner diameter of the opening 57 ofthe drive plate 56.

The clutch plate 50 of FIG. 8 is installed in a sealed clutch 26 and thesealed clutch 26 is installed in a clutch assembly 20, as shown in FIG.1 . Conveniently, the spline ring 66 is accessible in the assembledclutch assembly 20 and can be used or removed and replaced as necessaryto receive the splined portion or end of a transmission shaft.

Where any or all of the terms “comprise”, “comprises”, “comprised” or“comprising” are used in this specification (including the claims) theyare to be interpreted as specifying the presence of the stated features,integers, steps or components, but not precluding the presence of one ormore other features, integers, steps or components.

Those skilled in the art will appreciate that the invention describedherein is susceptible to variations and modifications other than thosespecifically described. It is understood that the invention includes allsuch variations and modifications which fall within the spirit and scopeof the present invention.

1. A sealed clutch including a spline connector for connecting thesealed clutch by splined connection to a transmission shaft of anautomotive transmission, the spline connector comprising a connectorhousing and a spline ring, the spline ring including an opening having aspline configuration for cooperating with a splined portion of atransmission shaft, the connector housing being secured within thesealed clutch and the spline ring being removably connectable to theconnector housing, to enable the spline ring to be removed and replacedwith a different spline ring for cooperating with a splined portion of adifferent transmission shaft.
 2. A sealed clutch according to claim 1,the connector housing including an opening and the spline ring beingsecured within the opening against relative rotation relative to theconnector housing.
 3. A sealed clutch according to claim 2, the splinering having an outer surface and the opening of the connector housingbeing configured to cooperate with the outer surface of the spline ringto locate the spline ring against rotation relative to the connectorhousing.
 4. A sealed clutch according to claim 3, the opening of theconnector housing being a non-round opening and the outer surface of thespline ring having a complementary shape and being closely receivedwithin the opening.
 5. A sealed clutch according to claim 3, the openingof the connector housing being generally circular and the spline ringhaving a generally circular outer periphery and being closely receivedwithin the opening of the connector housing and the spline ring beingconnected within the opening of the connector housing by a connectionarrangement.
 6. A sealed clutch according to claim 2, the opening of theconnector housing and the outer periphery of the spline ring each beinggenerally circular and one of the opening and the outer peripheryincluding one or more radially extending projections and the other ofthe opening and the outer surface including one or more radiallyextending recesses, whereby the one or more projections are receivedwithin the one or more recesses when the spline ring is received withinthe opening of the connector housing, to locate the spline ring againstrotation relative to the connector housing. 7.-8. (canceled)
 9. A sealedclutch according to claim 1, the sealed clutch including a pair ofspaced apart drive springs and each drive spring having opposite endsand the connector housing being in engagement with the opposite ends sothat rotation of the connector housing in a first direction of rotationis operable to apply a compressive load to the drive springs.
 10. Asealed clutch according to claim 9, the connector housing comprising aconnector body in which the opening for receipt of the spline ring isprovided and the connector housing having abutments extending from theconnector body into engagement with the opposite ends of the drivesprings.
 11. A sealed clutch according to claim 10, sealed clutch havinga central axis and the drive springs being located symmetrically onopposite sides of the central axis and being spaced apart equidistantlyabout the central axis, the connector housing having a pair of abutmentsextending from opposite sides of the connector body into engagement withthe opposite ends of the drive springs.
 12. A sealed clutch according toclaim 11, the drive springs being curved springs and the pair ofabutments having tapered side walls for engaging the opposite ends ofthe drive springs substantially normal to the axis of the ends of thedrive springs.
 13. A sealed clutch according to claim 1, including aclutch plate having a pair of drive plates that define an internalcavity between them and the spline connector being housed within thecavity, the drive plates each having a coaxially aligned opening throughwhich the splined portion of a transmission shaft can extend and theopening of the spline ring being coaxial with the openings of the driveplates, the spline connector being rotatable relative to the driveplates and the spline ring being removable through the opening of one ofthe drive plates.
 14. A sealed clutch according to claim 13, the outerdiameter of the spline ring being slightly less than the inner diameterof the opening of the drive plate through which the spline ring isremovable, and a removable retainer being provided to retain the splinering connected to the connector housing, whereby removal of theremovable retainer enables removal of the spline ring from the splineconnector through the opening of the drive plate.
 15. (canceled)
 16. Asealed clutch according to claim 13, a first axial end of the connectorhousing being rotationally seated against a facing surface of a first ofthe drive plates that extends about the opening of the first drive plateand a second and opposite axial end of the connector housing beingrotationally seated against a surface of a second of the drive platesthat extends about the opening of the second drive plate.
 17. A sealedclutch according to claim 16, including a wave or spring washerpositioned between the first axial end of the connector housing and afacing surface of a first of the drive plates to apply a biasing loadbetween the connector housing and the facing surface of the first driveplate.
 18. (canceled)
 19. A sealed clutch according to claim 17, havinga locator formed as a ring being interposed between the wave or springwasher and the first axial end of the connector housing, the locatorincluding projections that extend axially toward the second drive plateand that extend into engagement with the connector housing and which fixthe locator against rotation relative to the connector housing, and acircular lip extending axially away from the second drive plate and theouter diameter of the lip being a close fit within the inside diameterof the opening of the first drive plate.
 20. A sealed clutch accordingto claim 16, including a wave or spring washer positioned between thesecond axial end of the connector housing and a facing surface of asecond of the drive plates to apply a biasing load between the connectorhousing and the facing surface of the second drive plate. 21.-24.(canceled)
 25. A clutch plate having: a pair of drive plates that definean internal cavity between them, a spline connector for connecting theclutch plate by splined connection to a transmission shaft of anautomotive transmission being housed within the cavity, the splineconnector comprising a connector housing and a spline ring, the splinering including an opening having a spline configuration for cooperatingwith a splined portion of a transmission shaft, the connector housingbeing secured within the cavity and the spline ring being removablyconnectable to the connector housing, to enable the spline ring to beremoved and replaced with a different spline ring for cooperating with asplined portion of a different transmission shaft, the drive plates eachhaving a coaxially aligned opening through which the splined portion ofa transmission shaft can extend and the opening of the spline ring beingcoaxial with the openings of the drive plates, the spline connectorbeing rotatable relative to the drive plates, the outer diameter of thespline ring being slightly less than the inner diameter of the openingof one of the drive plates and a removable retainer being interposedbetween the spline connector and the drive plate to retain the splinering connected to the connector housing, whereby removal of theremovable retainer enables removal of the spline ring from the splineconnector through the opening of the drive plate.